Well i have tested it with 9V and after 20 sec it got pretty warm on the bottom near the power input when i was searching for a channel i immidiatly disconnected it because i got scared ! , further i dont smell any burning whatshowever i dont know what i should do.

So are the lower voltage AC Adapters that will work on Famicom readily available in the US?

I'm wondering if I should buy a couple extra in my last months here before coming back to the states... Keep stocked up just in case.

I don't k ow what you mean by 'readily available', but I have around 600 of them (NOS high quality, solid ones from the 90s, not the cheap-o junky featherweight ones made today) in stock. Available at local stores? That depends on the area...